Patent application title: CARD WITH DIGITAL DISPLAY

Abstract:

The invention relates to a card (38) including a digital display (10)
arranged in a node (4) defining the central portion of the card. It
further comprises a plastic layer (40) the major portion (42) of which is
opaque, and a transparent display portion (44). A pattern (14) is printed
on the upper face of the plastic layer (40), in particular by an offset
printing technique. The plastic layer (40) is covered with a transparent
film (12) attached thereto by a thin glue layer (34) defining an adhesion
interface. The electronic display (10) is fully integrated in the card
(38) and the printed pattern (14) exhibits a good contrast on the opaque
portion of said plastic layer. Furthermore, a good adhesion is obtained
between all the layers of the card.

Claims:

1-8. (canceled)

9. A card including an electronic display arranged in a core of said card,
characterized in that, above said core, said card has a plastic layer,
the greater part of which is formed of an opaque material and a display
part of which, located above said electronic display, is made of a
transparent material.

10. The card according to claim 9, wherein a pattern is printed on said
opaque greater part of said plastic layer or on the bottom surface of a
transparent external film arranged on said plastic layer so that the
printed pattern is located opposite said opaque greater part.

11. The card according to claim 9, wherein said opaque greater part of the
plastic layer is formed by a sheet that has an aperture in which said
transparent display part of said plastic layer is arranged.

12. The card according to claim 9, wherein the thickness of said plastic
layer is approximately constant.

13. The card according to claim 9, wherein said plastic layer is covered
by a transparent external film.

14. The card according to claim 9, wherein a layer of resin or adhesive is
arranged between the electronic display and the transparent display part
of said plastic layer.

15. The card according to claim 9, wherein said transparent display part
has a magnifying effect.

16. The card according to claim 15, wherein said display part defines a
Fresnel lens.

17. The card according to claim 11, wherein said plastic layer is covered
by a transparent external film.

18. The card according to claim 10, wherein a layer of resin or adhesive
is arranged between the electronic display and the transparent display
part of said plastic layer.

19. The card according to claim 11, wherein a layer of resin or adhesive
is arranged between the electronic display and the transparent display
part of said plastic layer.

20. The card according to claim 10, wherein said opaque greater part of
the plastic layer is formed by a sheet that has an aperture in which said
transparent display part of said plastic layer is arranged.

Description:

FIELD OF THE INVENTION

[0001]The present invention concerns a card incorporating an electronic
display. This electronic display is generally associated with an
electronic data processing circuit and, in some variants, with a switch
or sensor enabling a user to activate a certain function. The electronic
display can display variable codes and other data for increasing the
security of bankcards or secure access cards, for example. Integrating an
electronic display in a card causes a particular manufacturing
constraint, given that the card has to be transparent above the display.
The electronic display module is located inside the card according to the
invention. Thus, the display module is covered by at least one additional
outer protective layer.

BACKGROUND OF THE INVENTION

[0002]According to an advantageous method of manufacturing cards
incorporating various electronic elements, the electronic elements are
coated or embedded in a resin that forms a core or intermediate layer of
the card. EP Patent No. 0 570 784 generally discloses a manufacturing
method of this type. In order to obtain a core that has flat, uniform
surfaces, it is preferable to coat all of the electronic elements
incorporated in the card and thus to cover the electronic display with
the resin coating. In this latter implementation made, the resin must be
transparent at least in the display area. The transparency of the resin
causes a problem as regards obtaining high quality printing, in
particular on the top surface of the card where the display appears.
Consequently, it raises a dual problem. Generally speaking, printing
patterns on a transparent layer causes a decrease both in colour
intensity and contrast, so that the colours have a translucent
appearance. Secondly, the presence of various electronic elements in the
transparent core causes variations in light reflected by the core, which
results in darker areas on the surfaces of the core. The support on which
a pattern is printed is thus not optically uniform, which generally leads
to variations in contrast and variations in colour intensity on the top
surface side of the finished card.

[0003]In order to overcome the aforementioned problem, in manufactured
cards of the prior art, a light-coloured, preferably white, ink or
varnish is deposited underneath the printed patterns relative to the core
of the card, via a silkscreen printing technique, so that the thin layer
of ink or varnish has a certain thickness. Two variants of cards made in
accordance with this technique are shown in FIGS. 1 and 2.

[0004]Card 2 of FIG. 1 is formed of a core 4 incorporating an electronic
unit 8 and an electronic display 10. These electronic elements 8 and 10
are embedded in a transparent resin 6 that forms core 4, which is made in
a first step of a manufacturing method for such cards. Core 4 is formed
by a technique known to those skilled in the art, in particular in a
press or by injecting the resin into a mould. Next, a transparent film 12
is arranged on the top surface side of the core, on the inner surface of
which a pattern 14 is printed. To obtain high quality printing, i.e. high
definition, printed patterns 14 are preferably obtained by an offset
printing technique. Then, according to this prior art method, a layer of
ink or varnish 16 is printed on pattern 14. This layer 16 is preferably
white and it extends over the entire bottom surface of transparent film
12 except for the display area located above electronic display 10. Layer
16 thus defines a window through which electronic display 10 is visible.

[0005]Likewise, a transparent film 18 is arranged on the bottom surface
side of the card 2, on the top surface of which a pattern 20 is printed.
This pattern 20 is covered by a layer of ink or varnish 22. Layer 22 is
also preferably deposited by silkscreen printing. However, it should be
noted that bottom layers 16 and 22 might be deposited by various
techniques.

[0006]Card 22 according to the variant shown in FIG. 2 includes a core 24
formed of a resin or any material 26. Core 24 differs from core 4 of FIG.
1 in that the electronic display 10 at the top surface thereof is flush
with the top surface of core 24. Unlike the preceding variant, material
26 does not have to be transparent here. Material 26 may be added in
liquid form in a press or injection moulding installation, as for core 4
of FIG. 1. In another method of manufacturing core 24, electronic display
10 can be inserted in a shell with a preformed housing or in the aperture
of a layer forming core 24, which may be formed of one or several layers
assembled by lamination or by press bonding. In order to have a flat,
uniform support for printing pattern 14, a transparent film 30 is
arranged on the top surface of core 24. A layer of ink or varnish 16 is
deposited on the top surface of film 30, leaving a window for electronic
display 10. Pattern 14 is printed on this bottom layer 16 by an offset
technique. A transparent external film 12 is then assembled to printed
film 30. A fine layer of adhesive or resin is provided between printed
film 30 and external film 12 to increase adherence between these two
transparent films. On the bottom surface side of card 22, an opaque layer
32 is arranged against the core, on the bottom surface of which a pattern
20 is printed. This pattern 20 is then covered by a transparent external
film 18 by means of a thin layer of adhesive or resin 36.

[0007]Besides problems linked to the thickness of card 22, when developing
the present invention it was observed that embodiments of cards 2 and 22
did not efficiently resolve the previously identified problem, i.e. the
problem of a decrease in contrast and low colour intensity due to the
presence of a transparent layer or film behind the printed patterns 14.
Two major problems appear with the embodiments described with reference
to FIGS. 1 and 2.

[0008]First of all, the deposition of layer 16 by a printing technique
does not provide a perfectly opaque background. Various experiments have
demonstrated that it is necessary to deposit several layers particularly
by silkscreen printing in order to obtain an opaque background providing
a satisfactory visual appearance for high quality cards. Moreover, the
inks or varnish that can produce this opaque background 16 are the type
that have two components. Such inks or varnish have a relatively long
drying time, which raises several manufacturing problems. Thus, the time
necessary for printing or depositing several layers of varnish or ink for
the opaque background is considerable. This raises a storage problem
during the drying periods for each print or ink or varnish deposition.
This results in a relatively expensive manufacturing method requiring a
large storage capacity. This storage is not easy either since the printed
films must not be touched during the drying periods.

[0009]The second major problem is the problem of adherence of the
transparent external layer 12 in finished cards 2 and 22. The patterns 14
made by an offset printing technique adhere relatively poorly to the
transparent plastic film 12. To increase the adherence of this external
layer, printed pattern 14 is generally either covered with a thin layer
of adhesive or resin that adheres well to the transparent plastic film
used. If the two bottom layers 32 and 18 of card 22 are laminated to each
other with a printed pattern 20 and fine layer of adhesive 36 between
them, the adherence between layers 32 and 18 is sufficient. It was
observed that this is due to the fact that adhesive 34 slightly
penetrates the printed pattern and creates a multitude of anchorage
points with the layer or film on which pattern 20 is printed. In other
words, printed pattern 20 is sufficiently permeable to the adhesive for
the latter for form a real adherence interface between the two plastic
films or layers. The same effect is observed in the case of a similar
card to that of FIG. 1 where only printed patterns 14 and 20 are
provided. By selecting a resin 6 that adheres well to transparent layers
12 and 18, these layers have sufficient adherence to core 4 because resin
6 penetrates slightly printed patterns 14 and 20 during the card
lamination assembly operation. Thus, it has been observed that the
presence of the bottom layer forms a barrier to the adhesive or to the
resin such that they can no longer ensure the proper adherence of layer
12 in cards 2 and 22, and respectively of layer 18 in card 2.

SUMMARY OF THE INVENTION

[0010]After highlighting the various aforementioned problems in the
envisaged prior art solutions, shown in FIGS. 1 and 2, it is an object of
the present invention to propose a solution for overcoming the
aforementioned problems and to provide a card with an integrated
electronic display therein, yet which has a very high quality printed
pattern on the top surface thereof.

[0011]The present invention therefore concerns a card comprising an
electronic display, arranged in a core of said card, and above said core
a plastic layer, the greater part of which is formed of an opaque
material and of a transparent material in a display part located above
said electronic display. This transparent material defines a window for
reading the electronic display.

[0012]In a main variant, the plastic layer forms a printing support or
substrate for at least one printed pattern on the opaque part of the
plastic layer. Preferably, the opaque material is white.

[0013]In a preferred variant, the plastic layer is formed of a sheet made
of said opaque material, in which an aperture has been made in said
display area. A transparent plate is arranged in said aperture. The
thickness of the plate is preferably approximately equal to that of the
opaque sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]The present invention will be described in more detail in the
following description, made with reference to the annexed drawings, given
by way of non-limiting example, in which:

[0015]FIGS. 1 and 2 respectively show two transverse cross-sections of
cards made in accordance with a method prior to the present invention;

[0016]FIG. 3 is a transverse cross-section of a card according to the
present invention;

[0017]FIG. 4 shows an alternative embodiment of the card according to the
invention;

[0019]FIG. 6 shows schematically a first variant of a printed opaque sheet
that has windows filled with a transparent material; and

[0020]FIG. 7 shows how one part of the card shown in FIG. 3 is formed in
accordance with a specific manufacturing method.

DETAILED DESCRIPTION OF THE INVENTION

[0021]FIG. 3 shows an embodiment of a card according to the invention.
This card 38 has a core 4, similar to the core of card 2 of FIG. 1, in
which an electronic unit 8 and electronic display 10 are embedded. Core 4
is formed by a transparent resin 6, which also covers electronic display
10. The electronic elements are thus coated or embedded in resin 6, which
defines a compact core with two approximately flat surfaces. It will be
noted that, in other variants of the cores, the electronic elements are
merely covered by the resin without being entirely coated by said resin.

[0022]A layer 40, formed partly by an opaque material 42 and by a
transparent material 44, is arranged on core 4, above electronic display
10 such that the display is visible from outside card 38. The greater
part 42 of layer 40 is formed of opaque material, which is preferably
white. Only one aperture 46, defined by opaque part 42 in the display
area above electronic display 10, is filled by a transparent part 44.
This aperture 46 defines a window whose dimensions are such that only the
part used for the display of characters, numbers or other patterns of
display unit 10 is visible. The thickness of transparent part 44 is
approximately equal to that of opaque part 42. Thus, outside window 46,
layer 40 defines a perfectly opaque light-coloured background for
printing patterns 14 on the top surface of layer 40. Pattern 14 is
preferably printed by an offset technique. A transparent external layer
12 is arranged on printed layer 40, using a thin layer of adhesive 34
ensuring that external layer 12 adheres properly to intermediate layer
40. As previously explained, given that it is only necessary to print a
pattern, in particular in an offset printing installation, the thin layer
of adhesive really defines an adherence interface between layers 40 and
12. The problems mentioned in relation to cards 2 and 22 of the prior art
are thus solved by card 38 according to the invention.

[0023]In order to obtain a symmetrical card that also has a high quality
print on the bottom surface of the card, an opaque layer 32 is added, on
the bottom surface of which a pattern 20 is printed. Next, a transparent
external layer 18, coated with a thin layer of adhesive 36 is added
against printed sheet 32. The whole assembly is laminated in a press or
using laminating rollers to ensure its assembly. Cards are thus obtained
that have an integrated electronic display inside the card, visible
through transparent layers or films, while outside the display area there
is a print on a relatively thick opaque layer that allows very good
contrast and good colour intensity. It will be noted that one could
envisage having an electronic display on the bottom surface of the card
or on the two sides of the card.

[0024]Card 48 shown in cross-section in FIG. 4 is a variant made from a
similar core 24 to that of card 22 shown in FIG. 2. On the top surface of
core 24 there is a layer 40 of plastic material, the greater part 42 of
which is formed of an opaque material. In the display area located above
display unit 10, layer 40 has a part 44 formed of a transparent material.
A printed pattern 14 is provided on opaque part 42. The printed layer 40
is covered with a transparent film 12. In this variant, there is no thin
layer of adhesive between layer 40 and film 12. However, in another
variant, a film acting as adherence interface may be arranged between
layer 40 and external film 12. It will be noted that it is also possible
to provide a thin layer of resin or adhesive between plastic layer 40 and
core 24 to ensure that plastic part 40 adheres well to electronic display
10. This fine layer of adhesive is advantageously applied on the bottom
surface of layer 40 before assembly to core 24. The thin adhesive layer
may alternatively be deposited beforehand on the top surface of core 24
or be added in the form of a thin sheet arranged between layer 40 and
core 24. These different alternatives and variants also apply to the
arrangement of a fine layer of adhesive or resin between layer 40 and
external layer 12.

[0025]Pattern 14 can be printed, in a variant, on the bottom surface of
transparent film 12. This transparent film is then positioned such that
printed pattern 14 is opposite opaque part 42.

[0026]On the side of the bottom surface of core 24 an opaque layer 32 and
a transparent external film 18 are arranged, with a printed pattern 20
between them.

[0027]It will be noted that a transparent lacquer may replace transparent
external films 12 and 18, for example, or any other transparent material
that can protect printed patterns 14 and 20.

[0028]FIG. 5 shows a pierced plastic sheet 50 used to form layer 40 for a
plurality of batch-manufactured cards. The contour 58 of the cards,
obtained after cutting the finished cards from the batch, is represented
by a dotted line. The sheet 50 has an aperture 46 for each card. The
largest part 42 is formed by the opaque material of sheet 50,
particularly PVC. Patterns 14 can be printed on this sheet either before
making apertures 46, or after this operation. Printing beforehand
provides a printed pattern that perfectly surrounds the aperture provided
for each card.

[0029]FIG. 6 shows an intermediate product 52 involved in a first
implementation of a card manufacturing method according to the invention.

[0030]Intermediate product 52 is formed of sheet 50, shown in FIG. 5,
which defines a plurality of opaque parts 42 for a corresponding
plurality of cards. In apertures 46 of sheet 50 there are transparent
parts 44, which have approximately the same thickness as parts 42, so as
to form an intermediate product 52 that defines a flat structure. A
plurality of patterns 14 is printed on the top surface of sheet 50.
Transparent parts 44 are preferably formed by plates cut from a
transparent sheet and inserted into apertures 46. Plates 44 can be
obtained in other ways known to those skilled in the art.

[0031]Those skilled in the art can use various assembly techniques to
ensure that plates 44 remain in place until the step for laminating them
to the cores of the manufactured cards. For example, a few weld spots can
be made using a simple heated tool tip, applied to the edge of apertures
46. The plastic material melts locally, which creates weld spots and thus
assembles plates 44 to sheet 50. These weld spots are preferably made on
the bottom surface of sheet 50, i.e. on the side opposite the printed
surface. However, it is also possible to make these weld spots carefully
on the side of the printed surface, in particular when printing is
carried out subsequently. It is also possible to secure plates 44 using
an adhesive. This bonding step to keep transparent plates 44 in place may
be combined with the deposition of a thin layer of adhesive on the bottom
surface and/or the top surface of intermediate product 52. Transparent
plates 44 may also be assembled to pierced plate 50 in a laminating step.
It will be noted that this lamination may also be provided in addition to
the aforementioned spot assembly. Providing heat can thus at least
partially weld the lateral faces of the plates to the wall of the
corresponding apertures 46 and provide a flat, uniform layer. The layer
may then be used in a method of forming cards at a relatively low
temperature.

[0032]Intermediate product 52 is particularly advantageous for a method
where patterns 14 are printed after the opaque sheet has been assembled
to the transparent plates, as the printing can then also partially cover
the transparent plates.

[0033]The transparent parts 44 may, in another way of making cards
according to the invention, be obtained by injecting a transparent
material through windows 46.

[0034]FIG. 7 shows a cross-section of another intermediate product 54
obtained within a second implementation of a card manufacturing method
according to the invention. To obtain intermediate product 54, opaque
sheet 50 is first printed to obtain a plurality of patterns 14. Then, a
transparent film 12 covered with a layer of adhesive 34 is placed against
sheet 50 on the side of printed patterns 14. Printed sheet 50 is then
assembled to transparent film 12 and housings are obtained formed by
apertures 46 that have adhesive layer 34 at the bottom thereof.
Transparent plates 44 are then inserted into apertures 46 and secured to
film 12 via the locally heated adhesive layer, for example. An
intermediate product 54 is thus obtained which can then be assembled to a
core 4 or 24 to provide cards according to the present invention. It will
be noted that this intermediate product can also be obtained without the
adhesive layer. In this latter case, the temporary assembly is achieved
via a weld spot on one side or the other, on the edge of the apertures or
at the centre, by welding the plates to transparent film 12. Preferably,
the assembly thereby obtained is then laminated to obtain a properly
flat, multi-layered structure, without slots and without any marks that
could result from the temporary assembly of the transparent plates.

[0035]In a method where the core is not made in a prior step, but is
formed simultaneously while the whole card is being formed, intermediate
product 54 is then used as a top, multi-layered structure, arranged in
the laminating installation (flat press or rollers) on a resin in a
viscous liquid state used to form a central core incorporating the
electronic elements. A bottom sheet or multi-layered structure is
generally arranged underneath the resin that is added in the laminating
installation. Pre-assembled layers 18 and 32, as shown in FIG. 3 or 4,
may form this bottom multi-layered structure. The top and bottom
multi-layered structures are generally laminated at a relatively high
temperature, but the entire card is finally made at a low temperature or
ambient temperature, to prevent damaging the electronic elements.

[0036]It will be noted finally that transparent part 44 of plastic layer
40 may have various optical functions, particularly polarising or
filtering functions, and have undergone various treatments, particularly
an anti-reflective treatment. In an advantageous variant, this
transparent part defines a Fresnel lens, which gives a magnifying effect.
These functions or optical treatments are used first and foremost for
increasing the reading comfort of the electronic display. However, they
may also be used to give a certain visual or aesthetic appearance.